Postbags are generally considered canon, unless directly conflicting with lore in-game, in which case the latter has precedence.

Oo'glog Recreational Relaxation Resorts is the company of which Balnea is the CEO, that opened up a spa in Oo'glog. It is referenced in the 28th Postbag from the Hedge.[1] During As a First Resort..., the player helps to turn Oo'glog into a spa town, presumably administered by Oo'glog Recreational Relaxation Resorts.